Marketing Attribution: Working Out What Really Drove the Sale

When someone finally buys from you, which piece of marketing gets the credit? They might have found you through a Google search, returned via a social post, and only converted after clicking an email. Attribution is how you decide how to share the credit across those touchpoints.

It’s a genuinely tricky problem, and there are no perfect answers — but understanding the basics stops you cutting the very channels that quietly feed your best customers. Here’s how to think about it.

Why last-click is misleading

The default in many tools is last-click attribution, which gives all the credit to whatever the customer touched immediately before buying. It’s simple, but it badly undervalues everything that introduced and nurtured them along the way.

Imagine a customer who discovered you through an expensive but effective awareness campaign, then came back later via a branded search. Last-click hands all the glory to the cheap branded search and makes the awareness campaign look worthless — so you cut it, and your pipeline dries up.

The main models

First-click credits the channel that introduced someone. Linear shares credit equally across every touchpoint. Time-decay gives more credit to recent interactions. Position-based weights the first and last touches most. Data-driven models use your actual data to estimate each channel’s real contribution.

None is objectively correct. The right choice depends on your sales cycle and what you’re trying to learn. The key insight is simply that the model you pick changes the story your data tells — so be aware of which one you’re looking at.

A practical approach for small businesses

You don’t need a complex setup. Tag your links with UTMs, set up conversion tracking, and look at more than one attribution view rather than trusting a single number. Ask new customers how they found you too — that simple question often reveals what the data misses.

Above all, resist judging awareness-building channels purely on last-click sales. They rarely get the final click but often do the early work that makes later conversions possible. Honest attribution means valuing the whole journey, not just the finish line.